Mold box



Oct. 24, 1967 R. B. CORBETT 3,348,802

MOLD BOX Filed Sept. 22, 1965 2 Sheets-Sheet l lNvENToR Robert B.Corbett Oct. 24, 1967 R. B. coRBETT MOLD BOX 2 Sheets-Sheet 2 FiledSept. 22, 1965 INVENTOR Reben` B. Corbett United States Patent()3,348,802 MOLD BOX Robert Corbett, Mars, Pa., assignor of one-half eachto Sam Heppenstall & Associates, Inc., and Corbett AS- sociates, Inc.,both corporations of Pennsylvania Filed Sept. 22, 1965, Ser. No. 489,326Claims. (Cl. 249-163) The present invention relates to mold -boxes ofthe collapsible variety, and more particularly to a mold box of thecharacter described adapted for molding concrete blocks, test samples orthe like.

Concrete molds and the problems appertinent have long been known in theart. Such molds were usually fabricated from either various types ofwood or from steel, to which the concrete would readily adhere. In thecase of wood, the opened grained structure thereof presented a poroussurface into which the iiner particles of the concrete tended to flowand thereby to bond with the surface in a manner akin to a knittingaction. Therefore, it was diicult if not impossible, to remove thewooden mold portions without marring the surfaces of the concrete or ofthe mold. In the case of steel molds, the iron would tend to rust andform oxide coatings which would knit with the oxides of the cement usedin the concrete, with the result that the concrete would adhere ratherstrongly to the steel mold. Thus, removal of the steel mold was diicultand usually carried with it surface portions of the concrete castingresulting in an inferior surface condition. Plating the steel moldsurfaces alleviated the problem to some extent, until the removal of theplating by the abrasive character of the concrete again presented therust problem of the exposed steel surfaces.

Another problem in this area has been the lack of a concrete mold or thelike, from which the concrete block or casting can be quickly and easilyremoved without damage to the casting in its still green condition. Thisproblem is aggravated by the fact that the considerable weight of theconcrete or other material being cast tends to spring the side wallportions of the mold outwardly, which makes removal of the side wallsdii'licult, in the case of a collapsible mold structure, in addition tocausing dimensional distortion of the concrete casting. To combat thistendancy of the side walls to distort in this fashion, various fasteningmeans and braces have been employed therewith, which however, becomeembedded slightly in the concrete, so that removal of the casting fromthe mold becomes ditiicult in addition to presenting an undesirablesurface contour. Unfortunately, when the sides of the mold weredistorted in this fashion, leaks developed, causing undesirable loss ofwater from the concrete mixture and in extreme cases, losses of waterand of the concrete aggregate also. In this connection, no adequatemeans was provided in previous concrete mold structures for preventingleaks therefrom even in the absence of mold distortion. This problem fasparticularly diii'icult in the case of collapsible, re-usable moldstructures, as no adequate means were provided for properly clamping theparts together in a leak proof manner.

The foregoing difficulties were aggravated still further in the case oflight-weight portable mold structures of the collapsible variety. Thelatter mold structures find extensive use in making test samples ofconcrete or it is being poured in highway or building construction andin similar applications where it is important to ascertain the resultantstrength of the poured concrete after it has cured. Such test samplesmust be of uniform size and of good surface characteristics for propercomparison with standard sarnples or data obtained therefrom. It is alsoimperative that the mold structure admit of facile assembly anddisassembly to minimize the time required for making the test samplesand be of compact construction to facilitate its portability betweenpours or between jobs, as the case may be.

These problems are solved by the present invention which provides acollapsible mold box for concrete or the like, with a novel clampingmeans for vsecuring the sides and end wall components of the moldtogether in a closely fitting, substantially leak-proof manner and atthe same time for clamping the assembly thus formed to a bottom wallcomponent of the mold box in a similarly closely fitting, substantiallyleak-proof manner. With this arrangement, an essentially leak-proof moldstructure is provided, which ensures, in the case of concrete casting,

that little or no loss of the measured water added to the aggregate willbe lost before the concrete can set up.

Additionally, the novel mold structure includes a unique reinforcementmeans for the several wall components mentioned above which are arrangedon the outside of the mold structure, i.e., away from the internalsurfaces of the mold which engaged the charge of material pouredtherein. Where such reinforcing means cooperatively engaged two or moreof the wall components for assembly thereof as well as forreinforcement, such engagement is arranged so as not to interfere withthe substantially leakproof character of the junctions lbetween the wallcomponents.

In accordance with another feature of the novel mold structure, meansare associated with the aforementioned clamping means and are operableto aid in removing the clamping means and the wall component orcomponents secured thereto from the mold structure when it is desired toremove the molded material, such as the aforementioned concrete casting,therefrom.

Other features of the invention provide a particular arrangement ofreinforcing means whereby the aforementioned wall components can bereadily assembled and disassembled in order to utilize most fully thecollapsible character of the mold structure. It is also contemplated incertain arrangements of the mold structure, or for certain applicationsthereof such as for concrete casting, that 'the component parts thereofcan be fabricated from a structural material such as stainless steel towhich the aforementioned concrete will not strongly adhere. The absenceof rust formation on the stainless steel components, when used, obviatethe tendency of the concrete surfaces to knit with the adjacent surfacesof the mold structure, which will occur where rusted or other oxidecoated mold surfaces are employed, as noted previously.

These and other objects, features, and advantages of the invention,together with structural details thereof, will be elaborated upon duringthe forthcoming description of certain preferred embodiments of theinvention, together with presently preferred methods of practicing thesame.

In the accompanying drawings, I have .shown certain presently preferredembodiments of the invention and have illustrated presently preferredmethods of practicing the same, wherein:

FIGURE l is a top, end, and right side isometric View of one form ofmold structure arranged in accordance with the invention; v

FIGURE 2 is a top and end isometric view of the mold structureillustrated in FIGURE 1 and showing the side walls thereof insemi-collapsed position;

FIGURE 3 is a cross-sectional view of the mold structure as shown inFIGURE 1, and taken along reference plane III-III thereof;

FIGURE 4 is a top, left side, and end isometric partial view, somewhatenlarged of the mold structure shown in FIGURES l and 2, with the endwall removed;

FIGURE 5 is atop, left side, and end isometric partial view of the moldstructure shown in FIGURE 4 and illustrating the utilization of theclamp means and associated components for loosening parts of the moldstructure after the completion f the casting operation; and

FIGURE 6 is a top, left side and end isometric partial view of the moldstructure shown in FIGURES 4 and 5 with the end wall partially opened.

Referring now more particularly to the drawings, the illustrative formof the invention shown therein comprises a collapsible mold structuredenoted generally by the reference character 10. The mold structure 10includes a bottom wall member 12, as viewed in the drawings, which isreinforced in this arrangement of the invention by a pair of integrallyformed depending flanges 14 extending longitudinally of the bottom wallmember 12 at the lateral edge portions respectively thereof.

A pair of side wall members 16 and end wall members 18 are detachablyjoined to the bottom wall 12 and arranged thereon so as to form an opentop, generally rectangular structure. The side Walls 16 and the endWalls 18 respectively are reinforced at their upper lateral edges bymeans of out-turned flanges 20 and-22 extending generally longitudinallyof the side and end walls 16, 18.

The side and end walls 16, 18 are further reinforced adjacent theirlower edge portions by quick-detachable joining means whereby the sideand end walls are mounted on the bottom wall 12. .As seen in thedrawings one form of quick-detachable joining means includes a pluralityof depending tabs 24 secured on the outer surfaces of the side walls 16and positioned adjacent the lower lateral edges thereof so as to extenddownwardly thereof and into suitably placed slots 26 formed therefor inthe bottom wall 12. To facilitate assembly of the mold structure,desirably the tabs 24 fit rather closely in their respective slots 26 sothat the narrow slots and the thickness of the material comprising thetabs 24 and the bottom wall 12 produce a wedging action to maintain theside walls 16 in an intermediate collapsed position, as shown in FIGURE2 of the drawings, when not otherwise secured to the mold structure 10.This arrangement permits pre-positioning of the side wall members tofacilitate grasping and manipulating the same when assemblying the moldstructure 10. The slots 26 are further aligned with the bottom edge 28of the associated side wall 16 so as to align and reinforce the loweredge portion of the side wall 16 and to prevent bulging thereof when acharge of relatively heavy material such as concrete is poured into themold. Although three such tabs 24 are illustrated, it will be obviousthat a greater or lesser number can beremployed depending upon thelength of the mold structure, the thickness and strength of structuralmaterials from which the mold structure is fabricated, and the type andweight of charge poured into the mold structure.

In a similar manner, end walls 18 are provided with depending tabs 29cooperative with appropriately bottom wall slots 30 for detachablysecuring the end walls 18 to the bottom wall 12 and for reinforcing thelower portions thereof.

As evident from the various figures, particularly FIG- URE 3, thepositioning and reinforcing tabs 24, 29 and their slots 26, 30 aredisposed outwardly of the junction between the side wall bottom edges 28and the end wall bottom edges 32 so that the tabs 24, 29 will notcontact the charge and mar the surface of the resulting casting, and sothat the charge will not have access to the slots 26, 30 to leaktherethrough from the mold structure. In -further prevention of leaks inthe mold structure, the aforementioned bottom edges 28 and 32 of theside walls 16 and the end walls 18 respectively are made parallel to oneanother and otherwise disposed so as to lie in the same plane, and theupper or mold surface of the bottom wall 12 is likewise made planar andsmooth as possible so as to produce a closely fitting, leak-tightjunction between the side and end Walls 16, 18 and the aforementionedupper surface of the bottom wall 12 about the Ilower edge periphery ofthe vertical wall structure of the mold. As

described more fully below, clamping means are provided for maintainingthe aforementioned closely fitting relationship between the bottom wall12 and the normally vertical wall structure and also between the sidewalls 16 and the end walls 18 composing the vertical wall structure.

As shown in FIGURES l, 2, 5 and 6 of the drawings, the aforementionedclamping means, indicated generally by reference character 34, areassociated with each of the end plates 18. In this arrangement, eachclamping means 34 are provided with a T configuration including crossbar 36 and standard 38. The cross bar 36 thereof is mounted in a pair ofspaced, slotted brackets 40 secured on the outer surface of theassociated end plate 18 and disposed near the upper or anged edgethereof. The cross bar 36 when thus mounted is arranged for insertion ofits end portions respectively into the adjacent L-shaped slots 42 formedin the adjacent ends of the elongated side walls 16. The longitudinalslots 44 in the normally vertical, cross-bar brackets 40 (FIGURES 1 and5) are of sufficient length to allow the cross bar ends to be insertedinto and downwardly of the L-shaped notches 42.

As better shown in FIGURE 6, the cross bar brackets 40 are spacedinwardly from the vertical edges respectively, of the associatedendplate 18 so as not to interfere with drawing the adjacent surfaces ofthe side walls 16 tightly against the end wall vertical edges bytightening cross bar wing nuts 46, which threadedly engage the threadedend portions of the cross bar 36. In this example, the aforementionedend portions are formed by threading a pair of machine bolts 48 intodrilled and tapped apertures extending axially a short distance into theends of the cross bar 36. When thus secured, the heads of the machinebolts 48 prevent inadvertent unthreading and removal of the wing nuts46. The notches 26 along each lateral edge of the bottom wall 12 arespaced transversely thereof such that when the side walls 16 are raisedto their vertical positions against the end walls 18 the side wall tabs24 urige the side walls into close fitting engagement thereof with aleast the lower portions of the aforementioned end wall vertical edges,with the clamping engagement therebetween being completed, as describedbelow, by the clamping means 34, and in particular by the cross bar 36thereof and associated components.

As better shown in FIGURES 1 and 5 of the drawings, the end walls 18 arepositioned inwardly of the adjacent ends of the side walls 16 so thatthe vertical edges thereof are displaced inwardly of the side wallnotches 42. Desirably, the inward displacement of the end walls 18 isequal to the width of their top flanges 22 in order to lend a neatappearance to the mold structure and to minimize projecting corners andedges which may otherwise cause injury during use. In furtherance ofthis purpose, the outer corners of the side wall anges 20 are removedorv rounded off asfdenoted by reference characters 43.

When the side and end walls 16, 18 are assembled with the clamping means34 and with the aid of the wall tabs 24 and 29 and cooperatively spacedslots 26 and 30 of the bottom wall member 12, the vertical wall assemblythus for-med can then be clamped against the bottom wall member in orderto produce the aforementioned closefitting engagement therebetween foressentially leak proofing the mold structure 10. In furtherance of thispurpose, the standard 38 of each clamping means 34 is moved to thevertical position as shown in FIGURE 1 such that the lower end thereofis inserted into a notch 50 in the associated end of the bottom wall 12.Standard wing nut 52, which is threaded upon the lower threaded endportion of the standard 38, is then tightened to complete the clampingengagement of the clamping means 34 with the bottom wall 12, whereby thelower peripheral edges 28, 32 of the vertical wall structure 16, 18 arecompressed into engagement with the bottom wall member 12. Desirably,

the lower ends of the L-shaped notches 42 and of the cross bar slots 44are mated on the same elevational plane so that the cross bars 36 engageboth side walls 16 and the cross-bar brackets 40 of the associated endwalls 18 to apply clamping force to all components 16, 18 of thevertical wall structure when the standard wing nuts 52 are tightened,without relying necessarily on the mere frictional engagement of thesubsequently tightened cross bar wing nuts 46 with the side walls 16respectively. Following this operation the cross bar wing nuts 46 aretightened to complete the clamping engagement of the clamping means 34.

Means are also contemplated by the invention for facilitating openingand loosening the mold components from the material cast therein. Onearrangement of the lastmentioned means includes the provision of aslidably mounted impact member 54 on each of the clamping means 34. Inthis arrangement the impact member 54 is a heavy walled tubular memberthrough the axial opening of which the standard 38 is inserted. Theimpact member 54 is retained on the standard 38 at the upper end bymeans of the cross bar 36 and at the lower end by the standard wing nut52 and washer 56.

In order to loosen the vertical wall structure 16, 18 after the chargehas solidied, or set up and/ or c-ured in the case of concrete, clampingmeans wing nuts 48, 52 are loosened and the clamping means standard 38is angularly displaced outwardly from the Side wall a suicient -distanceso that the impact member 54 can be grasped and slid forcefully againstthe cross bar 36 in order to apply impacting forces to the end walls 18through cross bar 36 and .brackets 40. The impacting lforces thusdelivered to the end walls 18 need not be large since the relativelynon-adherent construction minimizes the adherent forces between the moldstructure components and the concrete or other charge.

Although stainless steel is desirable structural material for the sideand end walls 16, 18 and the bottom wall 12, in the case of concretecasting, it is to be understood that other suitable structural materialscan be utilized depending upon the application of the invention. Thosecomponents of the mold structure 10, such as the clamping means 34,which do not Contact the charge can, of course, be constructed fromordinary structural materials without regard to the charge or materialbeing cast in the mold structure. Thus, for example, the clamping means34 can be fabricated from ordinary carbon steel.

In the operation of the invention, for assembling the mold structure theside walls 16 and the end walls 18 are disposed at outwardly aredangles, and their tabs 24 or 29 are inserted into the respective bottomwall slots 26, 30 (FIGURE 2). Each of the tabs 24 and 29 are bentoutwardly as indicated `by reference characters S8 (FIGURE 3) tofacilitate inserting the tabs 24, 29 in their slots. The outwardly benttab portions 58 also serve to retain the vertical wall structure 16, 18upon the 4bottom wall 12 when the side and end wall are otherwisesecured in their vertical positions, in the event of inadvertent orpremature loosening of the standard wing nuts 52 of the clamping means34. For this purpose, the bottom wall slots 26 and 30 are suicientlynarrow that the tabs 24 and 29 are prevented from verticalv withdrawaltherefrom by engagement of the bent tab portions 58 with the adjacentouter edges of the slots.

After insertion of the side and end Walls, as depicted in FIGURE 2, theside walls 16 are then moved to their vertical positions as shown inFIGURE l and the end walls 18 are moved toward their vertical positionsWhile at the same time the clamping means cross bars 36 are movedupwardly in their bracket slots 44 so that the threaded end portionsthereof can be inserted into the L-shaped notches 42 of the side walls.The end walls are then positioned vertically whereupon the clampingmeans cross bars 36 drop to the bottoms of the notches 42 and thebracket slots 44. The clamping means 'are then pivoted about the axes oftheir cross bars 36 so that the lower ends of their standards 38 can beinserted into the bottom wall notches 50. The wing nuts 46, 52 of eachclamping means are then tightened to secure the Wall components 16, 18,12 together in the aforedescribed close tting, essentially leak-proofrelationship. Desirably the standard wing nuts 52 are first tightened toensure engagement of the entire lower edge periphery of the verticalwall structure 16, 18 with the adjacent bottom wall surfaces.

In order to remove a casting from the mold structure 10, the clampingmeans wing nuts 46, 52 are loosened and the clamping means standards 38are pivoted outwardly at a convenient angle' to the end walls 18 so thatthe impact members 54 can ybe readily manipulated to deliver impactingforces to the end walls 18. Only a few blows are required to loosen theend plates 18 from the casting. If desired, the cross bar wing nuts46can be retightened before impacting movements of the impact members 54,in order to ensure transmittal of the impact forces from the end walls18 in order to transmit the impacting forces directly to the side walls16 through the clamping engagement thereof with the end walls 18. Theimpacting forces also are transmitted to the bottom wall member 12 fromthe side and end walls 16, 18 by virtue of the side and end wallsresting edgewise upon the bottom wall member.

Following this operation, the side and end walls 16, 18 can be moved totheir semi-collapsed positions as shown in FIGURE 2, whereupon thecasting can be lifted from the bottom wall 12.

From the foregoing it will be apparent that novel and eicient forms ofmold structures have been disclosed herein. While I have shown anddescribed certain presently preferred embodiments of the invention andhave illustrated presently preferred methods of practicing the same, itis to be distinctly understood that the invention is not limited theretobut may be otherwise variously embodied and practiced within the scopeof the following claims.

I claim:

1. A mold structure comprising a bottom wall member, a plurality ofvertical wall members detachably joined to said bottom wall member, agenerally T shaped clamping member rotatably mounted on at least one ofsaid vertical wall members, said one vertical wall member extendingbetween a spaced opposed pair of said vertical wall members, and meansfor securing said clamping member to said opposed wall members and tosaid bottom wall member.

2. The combination according to claim 1 characterized in that each ofsaid vertical wall mem-bers has a number of depending tabs securedthereto adjacent the bottom edge thereof, said tabs being insertedrespectively into slots therefor in said bottom wall member.

3. The combination according to claim 2 characterized further in thatthe lower end portions of said tabs are bent from the plane of said tabsto prevent inadvertent removal of said vertical wall members from saidbottom wall member when said vertical wall members are disposed normalto said bottom wall member.

4. The combination according to claim 2 characterized further in thatsaid tabs and said slots are disposed outwardly of the junction betweenthe bottom edges of said vlertical wall members to prevent leakagethrough said s ots.

5. The combination according to claim 1 characterized in that an impactmember is slidably mounted upon said clamping member for movement in adirection therealong to deliver impacting forces to said one verticalWall member.

6. A mold structure comprising an elongated bottom wall member, a pairof spaced opposed side wall mem- Ibers detachably secured to said bottomwall member, a pai-r of spaced opposed end wall members extendinggenerally between said side wall members adjacent the ends thereofrespectively said end wall members being detachably secured to saidbottom Wall member, a generally T shaped clamping member rotatablymounted on each of said end walls, and means for detachably securingsaid clamping members to said side walls and to said bottom wall member.

7. The combination according to claim 6 characterized in that animpacting member is slidably mounted on each of said clamping membersfor movement therealong in a direction to deliver impacting blows to theassociated one of said end walls.

8. The combination according to claim 6 characterized in that an uppercross bar of each of said clamping members is rotatably and slidablymounted adjacent the upper edge of each of said end walls forcooperation with L- shaped notches formed in the adjacent edge portionsof said side Walls, and a standard for each of said clamping membersextends from the cross bar thereof to said bottom wall member, saidstandards being angularly displaceable relative to said end wallsrespectively for in sertion of said standards into retaining notchestherefor formed in the adjacent ends respectively of said bottom wallmember, said securing means being operable when said cross bars and saidstandards are inserted into said side wall notches and said bottom wallnotches respectively.

9. The combination according to claim 6 characterized in thatreenforcing anges are extended along the lateral edges of said bottomwall member and along the upper edges of said side walls and said endwalls respectively, said flanges being turned outwardly of the moldsurfaces of said side and said end walls and of said bottom wall member.

10. The combination according to claim 8 characterized in that animpacting member is slidably mounted on each of said clamping memberstandards and that said standards are further displacea'ble outwardly ofsaid end plates respectively so that impacting movements of said impactmembers along said standards and toward said end walls deliver impactingforces to said end Walls.

References Cited UNITED STATES PATENTS 799,493 9/ 1905 Pfeifer 249-163 X2,928,259 3/1960 Mundie 249-165 X FOREIGN PATENTS 1,188,499 3/ 1965Germany.

I. SPENCER OVERHOLSER, Primary Examiner.

HOWARD I. FLINT, JR., Examiner.

1. A MOLD STRUCTURE COMPRISING A BOTTOM WALL MEMBER, A PLURALITY OFVERTICAL WALL MEMBERS DETACHABLY JOINED TO SAID BOTTOM WALL MEMBER, AGENERALLY T SHAPED CLAMPING MEMBER ROTATABLY MOUNTED ON AT LEAST ONE OFSAID VERTICAL WALL MEMBERS, SAID ONE VERTICAL WALL MEMBER EXTENDINGBETWEEN A SPACED OPPOSED PAIR OF SAID VERTICAL WALL MEMBERS, AND MEANSFOR SECURING SAID CLAMPING MEMBER TO SAID OPPOSED WALL MEMBERS AND TOSAID BOTTOM WALL MEMBER.